摘要:
A design structure embodied in a machine readable medium used in a design process includes an apparatus for sensing the state of a programmable resistive memory element device, the apparatus further including a latch device coupled to a fuse node and a reference node, the fuse node included within a fuse leg and the reference node configured within a reference resistance leg, the latch device configured to detect a differential signal developed between the reference node and the fuse node as the result of sense current passed through the fuse leg and the reference resistance leg; and the fuse and reference resistance legs further configured for first and second sensing modes, wherein the second sensing mode utilizes a different level of current than the first sensing mode.
摘要:
A method for determining the state of a programmable resistive memory element includes passing a first level of current through a fuse leg and a reference resistance leg of a test circuit including the programmable resistive memory element; detecting a differential signal developed between a reference node and a fuse node of the test circuit as a result of the first level of current; passing a second level of current through the fuse leg and the reference leg of a test circuit, the second level of current being higher than the first level of current so as to enable detection of trip resistance of the test circuit at a lower value than with respect to the first level of current; and detecting a differential signal developed between the reference node and the fuse node of the test circuit as a result of the second level of current.
摘要:
A column redundancy system including a column redundancy apparatus for performing a redundancy swapping operation of column elements within the individual micro-cells. The column redundancy apparatus further includes a fuse information storage device, a first bank address decoding mechanism decodes a read bank address corresponding to a first micro-cell accessed for a read operation, and a second bank address decoding mechanism decodes a write bank address corresponding to a second micro-cell accessed for a write operation. If there is at least one defective column element contained within the first micro-cell, then the column redundancy apparatus generates an internal column address corresponding to the at least one defective column element in the first micro-cell. Likewise, if there is at least one defective column element contained within the second micro-cell, then the column redundancy apparatus generates an internal column address corresponding to the at least one defective column element in the second micro-cell.
摘要:
Disclosed is a flexible command multiplication scheme for the built-in-self test (BIST) of a high-speed embedded memory array that segments BIST functionality into remote lower-speed executable instructions and local higher-speed executable instructions. A stand-alone BIST logic controller operates at a lower frequency and communicates with a command multiplier using a low-speed BIST instruction seed set. The command multiplier uses offset or directive registers to drive a logic unit or ALU to generate “n” sets of CAD information which are then time-multiplexed to the embedded memory at a speed “n” times faster than the BIST operating speed.
摘要:
A method for allocating redundancies during a multi-bank operation in a memory device which includes two or more redundancy domains is described. The method includes steps of enabling a pass/fail bit detection to activate a given bank. The pass/fail bit detection is prompted only for a selected domain and is disabled when it addresses other domains. By altering the domain selection, it is possible to enable a redundancy allocation for any domain regardless of the multi-bank operation. The method may preferably be realized by using a dynamic exclusive-OR logic with true and complement expected data pairs. When combined with simple pointer logic, the selection of domains may be generated internally, simplifying the built in self-test and other test control protocols, while at the same time tracking those that fail.
摘要:
A row redundancy system is provided for replacing faulty wordlines of a memory array having a plurality of banks. The row redundancy system includes a remote fuse bay storing at least one faulty address corresponding to a faulty wordline of the memory array; a row fuse array for storing row fuse information corresponding to at least one bank of the memory array; and a copy logic module for copying at least one faulty address stored in the remote fuse bay into the row fuse array; wherein the copy logic module is programmed to copy the at least one faulty address into the row fuse information stored in the row fuse array corresponding to a predetermined number of banks in accordance with a selectable repair field size. Furthermore, a method is provided for replacing faulty wordlines of a memory array including the steps of: selecting a repair field size; storing at least one faulty address into a first memory; and copying the stored at least one faulty address from the first memory into a variable number of storage cells of a second memory, wherein each storage cell of said second memory corresponds to a respective bank of said plurality of banks; and wherein the variable number of storage cells is in accordance with the selected repair field size.
摘要:
In a DRAM, which includes a plurality of memory banks, there is a pair of separate flag bit registers for each bank with the flag bit registers that are shifted up/down respectively. A comparator for each bank provides a comparator output. An arbiter for each bank is connected to receive a flag bit up signal and a flag bit down signal from the flag bit registers for that bank and the comparator output from the comparator for that bank. The arbiters are connected to receive a conflict in signal and to provide a conflict out signal. The pair of flag bit registers represent a refresh status of each bank and designate memory banks or arrays that are ready for a refresh operation.
摘要:
A column redundancy system including a column redundancy apparatus for performing a redundancy swapping operation of column elements within the individual micro-cells. The column redundancy apparatus further includes a fuse information storage device, a first bank address decoding mechanism decodes a read bank address corresponding to a first micro-cell accessed for a read operation, and a second bank address decoding mechanism decodes a write bank address corresponding to a second micro-cell accessed for a write operation. If there is at least one defective column element contained within the first micro-cell, then the column redundancy apparatus generates an internal column address corresponding to the at least one defective column element in the first micro-cell. Likewise, if there is at least one defective column element contained within the second micro-cell, then the column redundancy apparatus generates an internal column address corresponding to the at least one defective column element in the second micro-cell.
摘要:
A secure device for electronic voting is employs a write-once vote-recording cartridge, preferably based on an e-fuse array. The cartridge has two distinct modes of operation: write mode and read mode. When in write mode, the array can only be written—it cannot be read. When in read mode, the array can only be read—it cannot be written. The array starts out in write mode. When switched to read mode, it cannot be switched back. A hardware mechanism provides successful write confirmation. The e-fuse array is installed (like a cartridge) into a vote-recording device. The voting device has an encryption/authorization mechanism that combines polling parameters (entered by the polling authority) with user (voter) information (Voter ID confirmation, poll selections, etc.) to produce a “fuse string” to be written into the e-fuse array. Upon completion of each vote, the fuse string from is written to the array, with hardware confirmation of successful writing. When all polling is complete, the poll is “closed” by switching the e-fuse array to the “read” mode, which permanently disables any further modification of the array. The encryption used to generate the “fuse string” values for each voter (user) renders the e-fuse contents meaningless to anyone except an auditor with proper authorization. In order to read out the results of the poll, an auditor must enter “password” information to decode/decrypt the contents of the e-fuse array.
摘要:
A memory system includes a memory array, a plurality of wordline drivers, a row address decoder block which has a plurality of outputs connected to selected ones of the wordline drivers, a row selector block which has a selector lines connected to individual ones of the wordline drivers. A power management circuit having a power down input for a power down input signal (WLPWRDN) and a wordline power down output (WLPDN) is connected to the wordline drivers to lower the power consumption thereof as a function of the power down input signal.